The present disclosure relates to a shift control system for an industrial vehicle.
A shift control system for an industrial vehicle known in the art, for example, which is mentioned in Japanese Patent Application Publication No. 2008-138700, upshifts and downshifts a transmission according to vehicle speed of the industrial vehicle.
Industrial vehicles such as forklift trucks having a vehicle speed limiting function have been adopted widely so as not to break a speed limit in a work place by a driver. Recent vehicle speed limiting function of an industrial vehicle allows limiting vehicle speed in small increments, such as at 5 km/h or at 1 km/h. Generally, the maximum vehicle speed of a forklift truck is about 20 km/h, and the forklift truck needs to perform upshifting and downshifting at a vehicle speed within a range of vehicle speed in which setting vehicle speed limit is allowable. If a vehicle speed limit value is set near the upshifting vehicle speed that is an expected vehicle speed at which upshifting the transmission is performed, upshifting may be performed at an unexpected speed that is greater than the upshifting vehicle speed due to road slope or conditions, which causes variation in timing of upshifting. One way to solve such a problem is not to allow the vehicle speed limit value to be set near the upshifting vehicle speed. However, this way may narrow a range of vehicle speed in which setting vehicle speed limit value is allowable, and may prevent the user of the forklift truck for limiting the speed of the forklift truck at a desired vehicle speed.
The present disclosure is directed to providing a shift control system for an industrial vehicle, which reduces variation in timing of upshifting without narrowing a range of vehicle speed in which setting a vehicle speed limit value is allowable.